CRYSTAL-AF: Cryptogenic Stroke and Underlying Atrial Fibrillation

2014, 30 Days AF monitoring in patients with Cryptogenic Stroke, NEJM

CRYSTAL AF Trial Summary

The Cryptogenic Stroke and Underlying Atrial Fibrillation (CRYSTAL AF) trial randomized 441 patients ,who were 40 years or older and with a diagnosis of cryptogenic stroke or transient ischemic attack within 90 days, in a 1:1 ratio to Insertable Cardiac Monitor (ICM) implantation or routine monitoring at the investigator’s discretion. Prior to randomization, all patients underwent at least 24 hours of ECG monitoring and had no evidence of atrial fibrillation at baseline. Patients were enrolled in 55 centers in Canada, Europe, and the United States. The primary endpoint was the time to first detection of atrial fibrillation, lasting >30 seconds, within 6 months. Approximately, 8.9% of patients in the ICM group were diagnosed with AF, compared with 1.4% in the control group (HR: 6.4; 95%CI: 1.9 to 21.7; p<0.001). Results were consistent through 12 months and 36 months.  Atrial fibrillation diagnosed in the ICM group was more frequently asymptomatic than in the control group. Prescription of oral anticoagulants was more than doubled in the ICM group, as compared with the control group, at both 6 and 12 months.